The present invention generally relates to a system and method for storing both open-format data and closed-format data, in multiple storage formats on a single storage medium, using a common indexing system. More particularly, the invention relates to a system and method for storing open and closed-format data on a storage medium, such that the open-format data can be accessed using both conventional and specialized hardware, whereas the closed-format data can only be accessed using specialized hardware capable of accessing data stored using multiple storage formats on a single storage medium for example using a common indexing system. More particularly still, the present invention relates to a system and method for storing open and closed-format data on optical storage media.
There are various types of random access media, including storage media for computer hard drives, CDs (compact discs), and DVDs (digital videodiscs or digital versatile discs). Both CDs and DVDs are examples of optical storage media Each type of random access media conforms to a standard, which specifies the characteristics of a medium, including an ensemble of at least the physical structure, the sector format, and a file system for referencing the files on a given medium, hereinafter xe2x80x9censemblexe2x80x9d.
An example of an ensemble can be found in the DVD specification for Read-Only Disc published by Toshiba Corporation.
A second example of an ensemble can be found in the industry standard ISO/IEC 10149:1995, titled xe2x80x9cInformation technologyxe2x80x94Data exchange on read-only 120 mm optical data disc (CD-ROM)xe2x80x9d. This is known in the industry as the xe2x80x9cYellow Bookxe2x80x9d standard and describes physical and logical file formats for CD_ROM.
A third example of an ensemble can be found in the industry standard IEC 60908 Ed. 1.0 b:1987, titled xe2x80x9cCompact disc digital audio systemxe2x80x9d. This is known in the industry as the xe2x80x9cRed Bookxe2x80x9d standard and applies to a pre-recorded optical reflective digital audio disc system. The Red Book defines those parameters of compact discs that affect interchangeability between discs and players. It is also intended as a reference for manufactures wishing to produce discs.and/or players that conform to the system described in this standard.
A standard ensemble for a particular storage medium ensures interoperability among different hardware implementations for accessing data on the medium. For example, an optical disc DVD conforming to a open video specification and containing the correct video formatting can be played or read by any DVD player that was designed to play DVDs conforming to that open-format DVD specification. The general techniques for organizing ensembles on DVD media and the standards used are described in DVD Demystified, by J. Taylor, McGraw Hill (1988), Chapters 3 and 4 as well as the particular DVD specification.
It may be desirable, however, to store data using different formats, e.g. a combination of video, CD audio, and DVD formats, on the same storage medium. This involves the use of a new type of hybrid disk which may contain separate (differentiated) physical structures, sector formats, and file systems on the same media.
Furthermore, in order to control access to data, it may be desirable to design disks having data stored in differentiated formats so that only specialized hardware can read or play all of the data on these disks, while allowing open-format hardware to read or play only a select portion of the data on these disks. Such differentiated playback can be achieved by implementing separate playback methods whereby access to data is limited on a partition by partition basis. For example, by changing the order in which the data bytes are stored within each sector, or by using a different error correction code (ECC) algorithm, encapsulation barriers can be imposed. If data in a closed-format (CF) partition is recorded using a CF ECC, the DVD player must be specially equipped to process this CF ECC data. In order to create specialized content that is inaccessible to conventional open-format (OF) hardware, other methods to arrange data in a closed-format or to encrypt data can also be used.
A method for making a single CD-ROM disc useable on computers having unrelated operating systems or for multi-media platforms is described in U.S. Pat. No. 5,359,725, issued to Garcia et al. However, this patent exemplifies the use of a single disk on two different operating systems, i.e., the Hierarchical File System (IFS) used by Macintosh computers, or MS-DOS, the operating system used by IBM and compatible personal computers. This system, using the CD-ROM standard ensemble stores the MS-DOS files directly and translates the Macintosh files into MS-DOS files with corresponding data and resource forks. In operation, this system uses a common ISO file system in conjunction with a translation layer thereby allowing either a MS-DOS based system or Macintosh based system to access all the files.
A method for storing data on multiple optical disk volumes in an optical disk autochanger is described in U.S. Pat. No. 5,579,516 issued to Van Maren et al. This patent describes a method of accessing data from a large data base; the data base consisting of a plurality of optical disks in an autochanger, by using readily addressable directories. Therefore, in this system, a plurality of files contained on a plurality of disks may be accessed from a single area of meta-data, which includes directory information and file information.
However, none of these systems provide a method or apparatus for accessing both OF and CF data, which coexists and interoperates on a single medium. What is needed is a method and apparatus for reading and/or writing data on a single storage medium in both OF and CF data structures.
It is an object of the invention to provide a single storage medium on which both open-format ensembles and closed-format ensembles co-exist.
It is another object of the invention to allow both open-format ensembles and closed-format ensembles to co-exist, and interoperate, on a single, hybrid storage medium.
It is another object of the invention to provide a method and apparatus for controlling access to data on random access storage media
It is yet a further object of the invention to permit enabled specialized hardware (e.g., a playback only system or a playback/write system) to access (i.e., read or read and write to) closed and open-format ensembles; wherein open-format hardware would be enabled to access only open-format data structures on that same media.
It is still a further object of the invention to allow specialized hardware to access data on a storage medium using either an open file system or an encapsulated (i.e., proprietary) closed-file system.
It is still a further object of the invention to allow open-format hardware to access data on a hybrid disc storage (i.e., a disc having both open-format and closed-format ensembles) medium using an open file system.
It is yet still a further object of the invention to provide a hybrid disc with a user message to inform the user that the disc is intended for play on a closed-system player when an attempt to play that disc on an open-format-only system player is attempted.
It is still a further object of the invention to provide a hybrid disc containing a multitude of different open and closed-format partitions, the number of partitions being limited only by the space on the disk.
It is still a further object of the invention to provide a disc and playback system wherein a user can manually select the content to be accessed when the user""s hardware is capable of playing a multitude of ensembles on a hybrid disc.
In general, in one aspect, the invention features a file storage structure for storing open-format data and closed-format data on a file storage medium. The structure comprises an encapsulated file area on the file storage medium referencing a first set of data on the file storage medium, a non-encapsulated file area on the file storage medium referencing the first and a second set of data on the file storage medium The first set of data and the second set of data is readable from within the non-encapsulated file area by a first data processing system, whereas the second set of data is only readable from the non-encapsulated file area by a second data processing system.
Preferably, one embodiment of the present invention further includes an indicator, indicating whether the file storage medium being accessed contains a closed-format data area Preferably, in this embodiment, the storage medium may be a DVD disc, and the indicator may be a specific file on the DVD disc. Furthermore, in this embodiment, the indicator preferably may comprise a transition file.
Preferably, another embodiment of the present invention includes a plurality of encapsulated, closed-format file areas and non-encapsulated, open format file areas.
Preferably, another embodiment of the present invention includes a transitional area between the non-encapsulated file areas and the encapsulated file areas. More specifically, transitional area may contain no content data Still further, a portion of the transition data area adjacent to the non-encapsulated file area may contain file data recorded using a non-encapsulated recording technique whereas a portion of the transition data area adjacent to the encapsulated file area may contain file data recorded using an encapsulated recording technique.
In general, in another aspect, the invention features a file storage structure for storing open-format data and closed-format data on a single storage medium. The structure comprises closed-format file area on the file storage medium referencing closed-format data on the file storage medium, and an open-format file area on the file storage medium referencing open-format and closed-format data on the file storage medium. The closed-format data and the open-format data is readable from within the closed-format file area by a first data processing system and only the open-format data is readable from the open-format file area by a second data processing system.
Preferably, one embodiment of the present invention includes an indicator, indicating whether the file storage medium being accessed contains a closed-format data area Further, this embodiment may preferably use a DVD disc as.the storage medium and a specific file on the DVD disc as the indicator. Still further, this indicator may be a transition file.
Preferably, in another embodiment of the present invention, the open-format file area is not encapsulated and closed-format file area is encapsulated into the open-format file area and further comprises a plurality of encapsulated and nonencapsulated file areas.
In general, in another aspect, the invention features a method of writing a file structure on a storage medium. The method comprises the steps of storing an encapsulated file close format or non-encapsulated closed-format onto a first area of the storage medium, the closed-format file referencing a first set of data stored on the storage medium and storing a non-encapsulated open-format file onto a second area of the storage medium, the non-encapsulated open-format file referencing a second set of data stored on the storage medium. The first set of data and the second set of data are readable from within the second area by a first open-format data processing system and the second set of data is only readable from said second area by a second data processing system having a closed-format reading capability.
In general, in yet another aspect, the invention features a method of reading a file structure from a storage medium. The method comprises the steps of reading an encapsulated or non-encapsulated closed-format file from a first area of a file storage medium exclusively by a first data processing system the encapsulated or non-encapsulated closed-format file referencing a first set of data on the storage medium, and reading a non-encapsulated open-format file from a second area of the storage medium with the first data processing system or a second data processing system, the non-encapsulated open-format file referencing the first and a second set of data on the storage medium.
Preferably, one embodiment of the present invention further includes accessing the encapsulated file using a non-encapsulated or open-format file directory in the second area. Further, this embodiment may preferably include determining from the non-encapsulated open-format file directory, the file sector of the encapsulated or non-encapsulated closed-format file to be accessed
In general, in still another aspect, the invention features a method of restricting access to data stored on a storage medium. The storage medium has both an open-format area, including an open-format directory and non-encapsulated data corresponding to the open-format directory, and a closed-format area, including a closed-format directory and encapsulated or non-encapsulated data corresponding to the closed-format directory. The method of restricting access comprises the steps of determining from the open-format directory a first logical sector number of the identification file of the data to be accessed, and determining from the open-format directory a second logical sector number of the file sector which contains the data to be accessed. When the second logical sector number is greater than or equal to the first logical sector number, data is accessed with a closed-format data reading device. On the other hand, when the second logical sector number is less than the first logical sector number, data is accessed with an open-format data reading device.
In general in still yet another aspect, the invention features a method of writing a file structure on a storage medium comprising the steps of storing a first file onto a first area of the storage medium, the first file referencing a first set of data stored on the storage medium, storing a second file onto a second area of the storage medium, the second file referencing a second set of data stored on the storage medium, wherein the first set of data and the second set of data are readable from within the second area by a first open-format data processing system and the second set of data is only readable from said second area by a second data processing system having a closed-format reading capability.
In general, in still another aspect, the invention features a method of reading a file structure from a storage medium comprising the steps of reading a first file from a first area of a file storage medium exclusively by a first data processing system, the first file referencing a first set of data on the storage medium, and reading a second file from a second area of the storage medium with the first data processing system or a second data processing system, the second file referencing the first and a second set of data on the storage medium.
Preferably, one embodiment of the present invention further includes accessing the first file using a file directory in the second area. This embodiment preferably further includes determining from the second file directory, the file sector of the first file to be accessed.
In general, in still another aspect, the invention features a method of restricting access to data stored on a storage medium. In this method, the storage medium has an open-format area, including an open-format directory and first data corresponding to the open-format directory, and a closed-format area including a closed-format directory and second data corresponding to the closed-format directory. The method comprises the steps of determining from the open-format directory a first logical sector number of the identification file of the data to be accessed. When the second logical sector number is greater than or equal to the first logical sector number, data is accessed with a closed-format data reading device. On the other hand, when the second logical sector number is less than the first logical sector number, data is accessed with an open-format data reading device.
The advantages of the invention include the provision of a storage medium designed to utilize an open file system, yet also incorporate an encapsulated or non-encapsulated closed file system, such that the two file systems can co-exist on a single storage medium. In addition, open-format hardware can access only select portions of data on the medium, whereas specialized (e.g., closed-format) hardware can access all data on the medium. This combination of file design and hardware allows different data structures to be stored on, and read or written from, a single medium.
Other objects, features, and advantages of the invention will become apparent from the following description and from the claims.